1. Field of the Invention
The present invention relates to a navigation device, in particular personal navigation apparatus for providing output data to a person identifying a route back to a recorded waypoint position, and a method of providing output data to a person identifying a route back to a recorded waypoint position.
2. Description of the Related Art
A person during a journey may experience an event that impairs the ability of that person to locate a safe position away from the position at which the event occurred. For example, a person may be diving in extreme conditions and may become disoriented and require guiding away from the event position.
Navigational systems are known. The two main techniques of navigation currently open to divers are dead reckoning, which involves following a compass bearing whilst simultaneously keeping track of distance and time, and pilotage, a combination of an underwater chart and clearly identifiable terrain features such as a reef. However, known navigational systems are impractical for a single person to transport conveniently. In addition, some navigational systems do not operate effectively in certain environments, such as underwater or underground, as they rely on fixed reference points.
A personal navigational apparatus that can operate without reference to a fixed reference point and can guide a person back to a safe position is therefore needed.